Method for manufacturing semiconductor device

• US 10,090,171 B2
• Filed: 11/21/2017
• Issued: 10/02/2018
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Sasaki, Toshinari, Sakata, Junichiro, Ohara, Hiroki, Yamazaki, Shunpei
• Primary Examiner(s): Bachner, Robert
• Application Number:
  US15/819,086
• Publication Number:
  US 20180218919A1
• Time in Patent Office: 315 Days
• Field of Search: None
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 21/383 using diffusion into or out of a solid from or into a gaseous phase
• CPC Class Codes: H01L 21/46 Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/428 manufacture of electrodes thereon H01L21/44
• CPC Class Codes: H01L 21/477 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/38 - H01L21/449 and H01L21/461 - H01L21/475 take precedence
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith.

Claims

1. A semiconductor device comprising:

a first conductive film over a substrate;

a first insulating film over the first conductive film;

an oxide semiconductor film over the first insulating film;

a second conductive film and a third conductive film over the oxide semiconductor film;

an oxide insulating film over the second conductive film and the third conductive film;

a second insulating film over the oxide insulating film; and

a fourth conductive film and a fifth conductive film over the second insulating film,

wherein the fourth conductive film is electrically connected to the third conductive film,

wherein a region of the fifth conductive film overlaps the first conductive film and the oxide semiconductor film, and

wherein the fourth conductive film and the fifth conductive film comprise the same material.

2. The semiconductor device according to claim 1,

wherein the oxide semiconductor film contains indium, gallium and zinc.

3. The semiconductor device according to claim 1,

wherein each of the second conductive film and the third conductive film has a stacked structure.

4. The semiconductor device according to claim 1,

wherein the second insulating film is a nitride film which is in contact with the oxide insulating film.

5. A display device comprising the semiconductor device according to claim 1.

6. An electronic equipment comprising the display device according to claim 5.

7. A semiconductor device comprising:

a first conductive film over a substrate;

a first insulating film over the first conductive film;

an oxide semiconductor film over the first insulating film;

a second conductive film and a third conductive film over the oxide semiconductor film;

an oxide insulating film over the second conductive film and the third conductive film;

a second insulating film over the oxide insulating film; and

a fourth conductive film and a fifth conductive film over the second insulating film,

wherein the fourth conductive film is electrically connected to the third conductive film,

wherein a region of the fifth conductive film overlaps the first conductive film and the oxide semiconductor film,

wherein the fourth conductive film and the fifth conductive film comprise the same material, and

wherein each of the fourth conductive film and the fifth conductive film comprises a transparent conductive film.

8. The semiconductor device according to claim 7,

wherein the oxide semiconductor film contains indium, gallium and zinc.

9. The semiconductor device according to claim 7,

wherein each of the second conductive film and the third conductive film has a stacked structure.

10. The semiconductor device according to claim 7,

wherein the second insulating film is a nitride film which is in contact with the oxide insulating film.

11. A display device comprising the semiconductor device according to claim 7.

12. An electronic equipment comprising the display device according to claim 11.